Ruggedized switchable glazing, and/or method of making the same

ABSTRACT

A coated article includes a low-E coating supported by a substrate (e.g., glass substrate), the low-E coating including first and second IR reflecting layers comprising silver and/or gold, and at least one UV blocking layer that blocks significant amounts of UV light having a wavelength of from 380-400 nm so that no more than about 20% of light having a wavelength of from 380-400 passes through the low-E coating. The UV blocking layer may be positioned so as to not directly contact the first and second IR reflecting layers.

This application is a divisional of application Ser. No. 11/987,005filed Nov. 26, 2007 now U.S. Pat. No. 8,199,264, the entire disclosureof which is hereby incorporated herein by reference in this application.

FIELD OF THE INVENTION

Certain example embodiments of this invention relate to ruggedizedswitchable glazings, and/or methods of making the same. Moreparticularly, certain example embodiments relate to liquid crystalinclusive (e.g., PDLC) layers that are protected using, for example,low-E UV-blocking coatings, PVB and/or EVA laminates, and/or PET layers.Certain example embodiments advantageously reduce one or more problemsassociated with residual haze, color change, flicker, structural changesin the polymer and/or the LC (liquid crystal), degradations instate-switching response times, delamination, etc.

BACKGROUND AND SUMMARY OF EXAMPLE EMBODIMENTS OF THE INVENTION

Polymer dispersed liquid crystals (PDLCs) typically are made by inducingphase separation in an initially homogeneous mixture of liquid crystaland monomers. Preparation of PDLCs involves a phase separation, which isconventionally triggered by polymerization of the monomer matrix byeither UV or thermal curing, or even rapid evaporation of solvents. Asthe monomer polymerizes, the liquid crystal phase separates intomicroscopic droplets or domains or pockets surrounded by the walls ofthe cured polymer matrix, which provides a “backbone” to hold the LC.The mixture of cured polymer and LC are held together between two sheetsof polyethylene (PET), often coated with transparent conducting oxides(TCOs) through which an electric field is applied. When unaddressed(e.g., when no voltage is applied), the nematic texture within thedomains is randomly oriented with respect to the other neighboringdomains, and the display appears whitish caused by the scattering oflight.

FIG. 1 a is a conventional PDLC glass window 100 in an off state. Twoglass substrates 102 a, 102 h are provided. A conductive coating 104 isapplied to the inner surface of the outer substrate 102 a (e.g., surface2 of the window assembly). A plurality of liquid crystal (LC) droplets108 are disposed within the polymer mixture 106. Because no voltage isprovided, the droplets 108 are randomly oriented, and incident light Ireflects off of them, causing the scattering of light in the directionsshown by the dashed arrows.

In the addressed state, the nematic texture in different domains alignwith the electric field, thus allowing for a clear state. FIG. 1 b is aconventional PDLC glass window 100 in an on state. FIG. 1 b is similarto FIG. 1 a, except that a voltage V is applied to the PDLC layer (e.g.,to the conductive coating 104) via one or more bus bars (not shown). Thevoltage causes the liquid crystal droplets to align parallel to theelectric field, allowing incident light I to pass through the window 100in the clear state.

Popular uses of this technology include glass walls in offices,conference rooms, lobbies, store fronts, etc. Privacy glass sometimes isused by homeowners (e.g., in bathrooms, entryways, family rooms,bedrooms, skylights, etc.). The windows may be made to function on astandard voltage and may be connected to switches. Windows also may beconnected to timers.

Unfortunately, although such techniques have represented an improvementin some windows, there still are certain drawbacks. Although theelectric field dramatically reduces the scattering, there still existsscattering at the boundary of the liquid crystal and polymer, andscattering between neighboring drops. This contributes in part to aresidual haze in the clear state. Another contribution to the residualhaze in the clear state relates to the polyvinyl butyral (PVB) orethylene-vinyl acetate (EVA) used to laminate the PDLC to the glass.

Furthermore, as another example drawback of current PDLC techniques,such windows suffer from UV and solar-induced degradation of the PDLClayer, ultimately causing color change and/or flicker. As used herein,“UV” refers to light having a wavelength less than or equal to about 400nm. More particularly, long-term exposure of the cured and laminatedPDLC to ambient UV light exacerbates the haze values and causes a“browning” of the LC (although such values are material dependent, afterabout 3,000 hours of UV exposure, generally ΔE*>2, with ΔE* being knownas a value indicative of color and transmission change of light, whereΔE*=sqrt((ΔL*)²+(Δa*)²+(Δb*)²), with L* corresponding to the “lightness”of the color, a* corresponding to the color's position between red andgreen, and b* corresponding to the color's position between blue andyellow). Even though the PVB layer cuts off about 99% of the UVradiation below about 380 nm, a large portion of UVA (e.g., having apenetration depth of long wavelength UVA in the order of magnitude ofPVB thickness) may still cause structural changes in both the polymer aswell as the LC, making determining the size of the droplets, and hencethe scattering function, difficult and susceptible to change. As usedherein, “UVA” refers to light having a wavelength from about 320 nm toabout 400 nm. The UV also may degrade and/or fade the colored PVBlayers. This susceptibility to degradation and/or fading is true fordye-based PVB, as well as in pigment-based PVB.

The degradation is exacerbated with temperature increases in the LCs.Because the thermal conductivity of the PVB, PET, and/or LC is low,radiation causes thermal runaways if samples are left exposed to the sunfor relatively long periods of time.

Another degradation of PDLC performance relates to the switching timesof the LC as its exposure to UV and heat increases. Response timeessentially is a function of the sum of the time on and time off(Ton+Toff). Initially, the response time of the device is just underabout 20 ms, which corresponds to a frequency of about 100 Hz. Thisfrequency is well above 25 Hz, which is generally regarded as thefrequency at which the human eye can perceive flicker. However, afterabout 1,000 hours of QUV accelerated weathering, the response time mayclimb above about 40 ms, which may make flicker noticeable to the humaneye.

Still another set of problems relates to delamination. Currently, curvedlaminates with sharp edges are susceptible to delamination in and/orproximate to high-stress hot-spots.

Thus, it will be appreciated that there is a need in the art for coatedarticles that overcome one or more of these and/or other disadvantages.It also will be appreciated that there is a need in the art for improvedPDLC techniques (for use in, for example, vehicle windows, insulatingglass (IG) window units, etc.).

In certain example embodiments of this invention, there is provided awindow (e.g., vehicle windshield, architectural window, or the like)comprising: an inner substrate and an outer substrate, the inner andouter substrates being substantially parallel to one another; amulti-layer low-E ultraviolet (UV) blocking coating supported by aninner surface of the outer substrate, the low-E UV blocking coatingblocking significant amounts of UV in the range of from about 380-400nm; a liquid crystal inclusive layer disposed between at least the innerand outer substrates; first and second substantially transparentconductive layers, the first and second substantially transparentconductive layers being provided between the liquid crystal inclusivelayer and the outer and inner substrates, respectively; first and secondpolymer inclusive laminating layers, the first laminating layer providedbetween at least the liquid crystal inclusive layer and the outersubstrate and the second laminating layer provided between at least theliquid crystal inclusive layer and the inner substrate; at least one busbar in electrical communication with the first and/or second transparentconductive layer(s) so as to cause the liquid crystal inclusive layer tobecome activated when a voltage is applied thereto; and wherein themulti-layer low-E UV blocking coating comprises at least one IRreflecting layer and at least one UV blocking layer so that no more thanabout 20% of ambient light having a wavelength of from 380-400 nmreaches the liquid crystal inclusive layer, and wherein the coatedarticle has a visible transmission of at least about 55% when the liquidcrystal inclusive layer is activated.

In certain example embodiments of this invention, there is provided acoated article including a low-E coating supported by a substrate, thelow-E coating comprising: first and second IR reflecting layerscomprising silver and/or gold; at least one UV blocking layer thatblocks significant amounts of UV light having a wavelength of from380-400 mm so that no more than about 20% of light having a wavelengthof from 380-400 passes through the low-E coating; and wherein the UVblocking layer is positioned so as to not directly contact the first andsecond IR reflecting layers. This coated article may be used in a windowunit or the like in different example embodiments of this invention, andthe substrate may be based on glass in certain example instances.

In certain example embodiments of this invention, a coated articleand/or a method of making the same is/are provided. An inner substrateand an outer substrate are provided. The inner and outer substrates aresubstantially parallel to one another. A multi-layer low-E UV blockingcoating is supported by an inner surface of the outer substrate. Aliquid crystal inclusive layer is disposed between the inner and outersubstrates. First and second transparent conductive layers are provided.The first and second transparent conductive layers are provided betweenthe liquid crystal inclusive layer and the outer and inner substrates,respectively. First and second laminate layers are provided. The firstlaminate layer is for lamination to the outer substrate, and the secondlaminate layer is for lamination to the inner substrate. At least onebus bar is operably connected to the liquid crystal inclusive layerthrough the first and/or second transparent conductive layer(s) so as tocause the liquid crystal inclusive layer to become activated when avoltage is applied to the at least one bus bar. The multi-layer low-E UVblocking coating is arranged so that no more than about 20% of lighthaving a wavelength of about 380-400 nm reaches the liquid crystalinclusive layer. The coated article has a visible transmission of fromabout 55-65% when the liquid crystal inclusive layer is activated.

In certain example embodiments of this invention, an insulating glassunit and/or a method of making the same is/are provided. Threesubstantially parallel substrates are provided. A multi-layer low-E UVblocking coating is supported by a surface of the second substratefacing the third substrate. A liquid crystal inclusive layer is disposedbetween the second and third substrates. First and second transparentconductive layers are provided. The first and second transparentconductive layers are provided between the liquid crystal inclusivelayer and the second and third substrates, respectively. First andsecond laminate layers are provided. The first laminate layer is forlamination to the second substrate and the second laminate layer is forlamination to the third substrate. At least one bus bar is operablyconnected to the liquid crystal inclusive layer through the first and/orsecond transparent conductive layer(s) so as to cause the liquid crystalinclusive layer to become activated when a voltage is applied to the atleast one bus bar. The first and second substrates are spaced apart. Themulti-layer low-E UV blocking coating is arranged so that no more thanabout 20% of light having a wavelength of about 380-400 nm reaches theliquid crystal inclusive layer. The insulating glass unit has a visibletransmission of from about 55-65% when the liquid crystal inclusivelayer is activated.

In certain example embodiments of this invention, a coated articleincluding a low-E UV blocking coating supported by a substrate and/or amethod of making the same is/are provided. The low-E UV blocking coatingcomprises first and second IR reflecting layers comprising silver and/orgold, and a UV blocking layer that blocks light having a wavelength ofabout 380-400 nm so that no more than about 20% of such light penetratesthe coating. The coated article has a visible transmission of at leastabout 55%.

In certain example embodiments of this invention, an insulating glass(IG) unit including a low-E UV blocking coating supported by a substrateand/or a method of making the same is/are provided. The low-E UVblocking coating comprises first and second IR reflecting layerscomprising silver and/or gold, and a UV blocking layer that blocks lighthaving a wavelength of about 380-400 nm so that no more than about 20%of such light penetrates the coating. The IG unit has a visibletransmission of at least about 55%.

The features, aspects, advantages, and example embodiments describedherein may be combined to realize yet further embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages may be better and morecompletely understood by reference to the following detailed descriptionof exemplary illustrative embodiments in conjunction with the drawings,of which:

FIG. 1 a is a conventional PDLC glass window in an off state;

FIG. 1 b is a conventional PDLC glass window in an on state;

FIG. 2 is a cross-sectional view of a window in accordance with anexample embodiment of this invention;

FIG. 3 is a cross-sectional view of an insulating glass (IG) window unitin accordance with an example embodiment of this invention;

FIG. 4 is a graph of experimental data that illustrates the generalineffectiveness of the PVB in containing the UVA incidence (the verticalaxis of the graph represents percent transmission, and the horizontalaxis of the graph represents wavelength in nm);

FIG. 5 is a graph of experimental data that illustrates the advantagesgained by ruggedizing the PDLC in accordance with an example embodiment(the vertical axis of the graph represents percent transmission, and thehorizontal axis of the graph represents wavelength in nm);

FIG. 6 is an example multi-layer low-E UV blocking coating that may beused in connection with certain example embodiments; and

FIG. 7 is another example multi-layer low-E UV blocking coating that maybe used in connection with certain example embodiments.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

Certain example embodiments provide PDLC windows using an effectiveblocking layer as well as a double or triple silver layer so as toreduce the incidence of the PDLC warming and therefore help to solve ofone or more of the above-described and/or other problems associated withconventional PDLC techniques. The UV blocking layer preferably has atleast about 99.5% UV cut-off below 410 nm. In certain exampleembodiments, the UV blocking layer is temperable. Certain exampleembodiments therefore may advantageously reduce one or more problemsassociated with residual haze, color change, flicker, structural changesin the polymer and/or the LC, degradations in state-switching responsetimes, delamination, etc.

FIG. 2 is a cross-sectional view of a window in accordance with anexample embodiment. In the window of FIG. 2, two substrates (e.g., glasssubstrates) are provided, including an outer substrate 202 and an innersubstrate 204. A low-E UV blocker 206 is deposited on the inner surfaceof the outer substrate 202. The low-E coating 206 may be, for example,of the type disclosed in U.S. Pat. No. 7,056,588 or 6,887,575, orapplication Ser. No. 11/281,598, the entire contents of each of which ishereby incorporated herein by reference. The low-E coating 206 also mayinclude one or more infrared reflecting (IR) layers in certain exampleembodiments. Furthermore, the low-E coating may include one or more UVblocking layers, or a separate UV blocking coating may be applied, e.g.,proximate to one or more of the low-E coatings described above. Furtherdetails of an example low-E UV blocking layer are provided below, e.g.,with reference to FIGS. 6 and 7.

A first laminate layer 208 comprising a polymer-based material (e.g.,PVB and/or EVA) is applied over the low-E UV blocking coating 206proximate to surface 2 of the window. A second laminate layer 208 alsocomprising a polymer-based material (e.g., PVB and/or EVA) is applied onthe inner surface of the inner substrate 204 (on surface 3 of thewindow). The first and second laminate layers 208 may be applied to therespective surfaces, via rolling and cured via an autoclaving process,for example.

The liquid crystal inclusive (e.g., PDLC) layer 214 is disposedapproximately in the center of the cross-sectional stack shown in FIG.2. Sandwiching the PDLC 214 are first and second TCO layers 212. Thefirst and second TCO layers 212 may be of, or include, for example,ZnAlO_(x), SnO_(x):F, SnSbO_(x), or the like, in certain exampleembodiments. The TCO layers may be sputtered onto one or both surfacesof the PDLC 214 and/or the respective surfaces of the first and secondpolymer-based (e.g., PET) layers 210 that are more proximate to the PDLC214.

First and second polymer-based layers 210 are provided between the firstand second laminate layers 208 and the first and second TCO layers 212,respectively. The first and second polymer-based layers 210, the firstand second laminate layers 208, and the low-E UV blocking coating 206extend at least the width of the PDLC 214 so as to protect it.

One or more bus bars are provided, e.g., to provide voltage to the PDLC214, either directly or indirectly. In certain example embodiments, twobus bars are respectively connected to the first and second TCO layers212. A groove or channel is cut in each of the first and second laminatelayers 208. In certain example embodiments, when viewed in crosssection, the grooves may be substantially U-shaped, with the firstgroove being upwardly oriented and the second groove being downwardlyoriented. Also, in certain example embodiments, the grooves may bedisposed at opposing corners of the PDLC stack, e.g., such that thefirst groove is disposed in the upper left corner of the PDLC stackwhile the second groove is disposed in the lower right corner of thePDLC stack. Of course, it will be appreciated that the foregoingdescription is provided by way of example and without limitation andthat other arrangements may be used in connection with certain otherexample embodiments (e.g., when only one bus bar is used, whendifferently shaped channels are formed, etc.).

Each groove may be formed by laser cutting (e.g., using a CO₂ laser),using a half-cutter, or via any suitable means. The groove is filledwith a silver paste, and a flat wire ribbon is bonded thereto. Voltagemay be provided through this ribbon so as to cause the PDLC 214 tobecome activated. The voltage may be connected to a switch (not shown)in certain example embodiments.

FIG. 3 is a cross-sectional view of an insulating glass (IG) window unitin accordance with an example embodiment. FIG. 3 is similar to FIG. 2.For example, the same liquid crystal inclusive (e.g., PDLC) stack of alow-E UV blocking coating 206, a first laminate layer 208, a firstpolymer-based (e.g., PET) layer 210, a first TCO layer 212, the PDLC214, a second TCO layer 212, a second polymer-based (e.g., PET) layer210, and a second laminate layer 208 are provided between second andthird substrates (e.g., glass substrates) 202, 204. However, as shown inFIG. 3, a first substrate 302 (e.g., glass substrate) is locatedproximate to the second substrate 202. The first and second substrates302, 202 are separated, e.g., by an air gap 304, so as to provideinsulating features for the IG unit. The three substrates aresubstantially parallel to one another.

Thus, the example embodiment shown in and described with reference toFIG. 3 may be thought of as being a conventional IG unit, with the low-EUV blocking coating conventionally found on surface 2 of the windowbeing moved to surface 4 of the window, along with the other elements ofthe PDLC stack of certain example embodiments.

Also, in connection with certain of the example IG units describedherein, a low-E (and/or UV or UVA blocking) layer may be provided onsurface 2 of the window (e.g., on the inner surface of the firstsubstrate 302 proximate to the air gap 304) in certain exampleembodiments. This low-E layer may augment or replace the low-E UVblocking coating 206 located on the inner surface of the secondsubstrate 202, depending on the illustrative implementation chosen.

In certain example embodiments, the periphery of the stack is left open(e.g., not sealed). However, in certain other example embodiments, aseal (e.g., a polymer-based seal) may be provided around the peripheryof the window and/or at least the PDLC stack, so as to reduce the amountof water, debris, etc., from entering into the unit.

FIG. 4 is a graph of experimental data that illustrates the generalineffectiveness of the PVB in containing the UVA incidence. The graphshows the transmission of visible light (Tvis) and the reflectance ofvisible light (Rvis) of a full laminate with clear PVB in the 300 to 500nm range. Light having a wavelength above about 400 nm (e.g., from about400 nm to about 700 nm) typically is visible. The sample tested was apiece of clear glass, 1.7 mm thick. In FIG. 4, line 402 corresponds totransmission of light, line 404 corresponds to inward reflection, andline 406 corresponds to outward reflection. As can be seen from FIG. 4,about 99% of UV transmission is blocked up to about 380 nm. However, theUV transmission increases markedly thereafter. The reflection in and outis very low throughout all wavelengths. Thus, as will be appreciatedfrom FIG. 4, the PVB alone does little to block UVA incidence andprovides low inward and outward reflection (also resulting in, forexample, poor insulating features and leading to one or more of theabove-described and/or other drawbacks).

By way of contrast, FIG. 5 is a graph of experimental data thatillustrates the advantages gained by ruggedizing the PDLC in accordancewith an example embodiment. More particularly, Tvis and Rvis are shownfor a half-laminate with a double silver low-E and UV blocking filmbeing disposed on surface 2 of the window, in accordance with an exampleembodiment. The sample tested was clear glass, coated with SunGuard SN68 and ClimaGuard SPF (both commercially available from Guardian) andincorporating a 0.030″ PVB laminate layer, bringing the total thicknessto about 3 mm. In FIG. 5, line 502 corresponds to transmission of light,line 504 corresponds to inward reflection, and line 506 corresponds tooutward reflection. Unlike the arrangement that produced the results ofFIG. 4 in which the PVB alone does not block light having a wavelengthfrom about 380-400 nm, the arrangement of FIG. 5 and of certain exampleembodiments includes a low-E and UVA blocking layer that does blocklight having a wavelength from about 380-400 nm. There is an average ofabout 65%, transmission between about 400 nm and 650 nm. Tvis fallsrapidly until about 900 nm, and is greatly reduced above about 1300 nm.Reflection in and out range from about 5% to about 10% in the wavelengthrange of about 300-600 nm, and then climb markedly starting at about 600nm. Thus, as will be appreciated from FIG. 5, substantially more UVAincidence is blocked, and Rvis is higher at substantially allwavelengths. There is also good transmission of visible light.

The following table provides additional experimental data, showing thechanges in haze, E*-value, and percent of visible transmission invarious test samples from “0-hour” UV exposure over a number ofdifferent UV exposure times produced according to certain exampleembodiments. For example, a*=a*₁−a*₀, with a*₀ being the a* value after0 hours of UV exposure, b*=b*₁−b*₀, with b*₀ being the b* value after 0hours of UV exposure, L*=L*₁−L*₀, with L*₀ being the L* value after 0hours of UV exposure, etc. As can be appreciated from the table below,the samples created in accordance with certain example embodimentsheld-up very well in terms of changes in haze, E*-value, and percent ofvisible transmission, even after over 3,000 hours of UV exposure. Unlessotherwise noted, the procedure for gathering the data in the tableinvolved measuring each sample twice in the off state. Then, each samplewas measured twice in the on state after waiting approximately 4minutes. The data provided below represents the average of the twomeasurements. It was discovered that on state values are cyclical and donot always stabilize.

Sample 4 provides a comparative example, in that one-half of the sampledid not have a UV blocking coating, whereas the other half of the sampledid have a UV blocking coating, L*, a*, and b* represent transmissivemeasurements.

Sample # Sample 1 Sample 2 Sample 3 Sample 4 Sample 4 Type UV UV BlockerUV Blocker UV Blocker ½ no UV Blocker ½ UV Blocker Time State (hrs) OffOn Off On Off On Off On Off On 0 Haze 101 5.95 102 6.68 102 6.94 1027.62 102 7.62 % Tvis (Y 2/C) 1.66 72.09 1.29 70.65 1.23 67.52 1.3168.21   1.31 68.21 L* (2/C) 13.57 88.01 11.19 87.31 10.81 85.77 11.3686.11 11.36 86.11 a* (2/C) 4.61 −0.75 2.36 −0.76 2.46 −1.57 1.98 −1.151.98 −1.15 b* (2/C) 9.17 5.38 6.44 5.61 6.52 8.09 6.13 4.98 6.13 4.98336 Haze 101 5.92 102 6.80 102 7.07 102 7.22 102 7.71 % Tvis (Y 2/C)1.64 70.99 1.32 68.59 1.19 68.53 1.56 67.24 1.47 68.75 L* (2/C) 13.4887.48 11.40 86.29 10.47 86.27 12.97 85.62 12.38 86.38 a* (2/C) 4.70−0.51 2.57 −0.99 1.79 −0.91 3.41 −0.85 2.63 −0.82 b* (2/C) 9.09 5.266.57 6.90 5.44 6.63 8.25 5.45 6.97 4.43 Δ Haze 0.0 0.0 −0.5 0.1 −0.5 0.10.0 −0.4 0.0 0.1 Δ % Tvis (Y 2/C) 0.0 −1.1 0.0 −2.1 0.0 1.0 0.3 −1.0 0.20.5 ΔE* 0.2 0.6 0.3 1.7 1.3 1.7 3.0 0.7 1.5 0.7 672 Haze 101 6.15 1026.77 102 7.02 102 7.43 102 7.74 % Tvis (Y 2/C) 1.74 70.50 1.32 69.441.24 68.87 1.45 67.11 1.41 68.72 L* (2/C) 14.06 87.24 11.41 86.72 10.8686.43 12.30 85.56 12.03 86.36 a* (2/C) 5.07 −0.66 2.63 −0.78 2.04 −0.903.14 −0.72 2.56 −0.78 b* (2/C) 9.81 5.66 6.57 5.62 5.88 6.47 7.70 5.606.87 4.53 Δ Haze 0.0 0.2 −0.5 0.1 −0.5 0.1 0.5 −0.2 0.0 0.1 Δ % Tvis (Y2/C) 0.1 −1.6 0.0 −1.2 0.0 1.4 0.1 −1.1 0.1 0.5 ΔE* 0.9 0.8 0.4 0.6 0.31.9 2.2 0.9 1.2 0.6 1008 Haze 101 6.04 102 6.76 102 7.03 102 7.39 1027.76 % Tvis (Y 2/C) 1.74 69.88 1.30 68.74 1.24 67.31 1.42 66.66 1.3968.36 L* (2/C) 14.07 86.93 11.28 86.38 10.84 85.66 12.10 85.33 11.8786.19 a* (2/C) 5.09 −0.78 2.54 −0.98 2.05 −1.33 3.01 −0.74 2.54 −0.76 b*(2/C) 9.79 6.19 6.47 6.46 5.84 7.95 7.64 5.81 6.73 4.65 Δ Haze 0.0 0.1−0.5 0.1 −0.5 0.1 0.5 −0.2 0.5 0.1 Δ % Tvis (Y 2/C) 0.1 −2.2 0.0 −1.90.0 −0.2 0.1 −1.6 0.1 0.2 ΔE* 0.9 1.4 0.2 1.3 0.3 0.3 2.0 1.2 1.0 0.51344 Haze 101 6.42 102 6.86 102 7.29 102 7.415 102 7.81 % Tvis (Y 2/C)1.67 70.47 1.33 69.06 1.21 69.62 1.49 66.28 1.42 68.16 L* (2/C) 13.6787.23 11.45 86.54 10.60 86.81 12.53 85.14 12.08 86.09 a* (2/C) 4.66−0.59 2.79 −0.83 1.87 −0.55 3.42 −0.73 2.74 −0.79 b* (2/C) 9.25 5.626.65 6.26 5.53 5.29 8.29 6.06 7.01 4.82 Δ Haze 0.0 0.5 −0.5 0.2 −0.5 0.40.5 −0.2 0.5 0.2 Δ % Tvis (Y 2/C) 0.0 −1.6 0.0 −1.6 0.0 2.1 0.2 −1.9 0.1−0.1 ΔE* 0.1 0.8 0.5 1.0 0.6 3.2 2.8 1.5 1.4 0.4 1680 Haze 100.5 5.93101.5 6.65 100.85 6.985 102 7.62 102 7.47 % Tvis (Y 2/C) Data 71.03 1.3069.95 Data 69.85 1.42 66.00 1.42 67.33 L* (2/C) missing 87.50 11.2686.98 missing 86.92 12.11 84.99 12.08 85.67 a* (2/C) −0.55 2.55 −0.57−0.59 3.07 −0.75 2.75 −0.88 b* (2/C) 5.45 6.45 5.58 5.37 7.89 6.30 7.085.05 Δ Haze −0.5 0.0 −0.5 0.0 −1.2 0.1 0.5 0.0 0.5 −0.2 Δ % Tvis (Y 2/C)−1.1 0.0 −0.7 2.3 0.1 −2.2 0.1 −0.9 ΔE* 0.6 0.2 0.4 3.1 2.2 1.8 1.4 0.52016 Haze 102 6.02 102 6.63 102 6.97 102 7.53 102 7.4 % Tvis (Y 2/C)1.73 70.53 1.30 69.77 1.235 69.93 1.47 65.47 1.56 65.49 L* (2/C) 14.0187.26 11.28 86.89 10.81 86.97 12.37 84.73 12.97 84.74 a* (2/C) 5.10−0.66 2.60 −0.59 2.125 −0.51 3.14 −0.72 3.39 −1.46 b* (2/C) 9.85 5.596.56 5.62 5.885 5.39 8.25 6.53 8.13 7.36 Δ Haze 0.5 0.1 0.0 0.0 0.0 0.00.5 −0.1 0.5 −0.2 Δ % Tvis (Y 2/C) 0.1 −1.6 0.0 −0.9 0.0 2.4 0.2 −2.70.3 −2.7 ΔE* 0.9 0.8 0.3 0.5 0.3 3.1 2.6 2.1 2.9 2.8 2352 Haze 101 5.88102 6.66 102 6.93 102 7.43 102 7.395 % Tvis (Y 2/C) 1.71 71.09 1.3269.70 1.23 69.88 1.48 65.42 1.48 65.31 L* (2/C) 13.88 87.53 11.39 86.8510.80 86.94 12.45 84.70 12.51 84.64 a* (2/C) 5.04 −0.55 2.66 −0.61 2.12−0.54 3.37 −1.37 3.17 −0.81 b* (2/C) 9.76 5.59 6.67 5.67 5.90 5.44 8.557.24 7.84 6.69 Δ Haze 0.0 −0.1 0.0 0.0 0.0 0.0 0.5 −0.2 0.5 −0.2 Δ %Tvis (Y 2/C) 0.1 −1.0 0.0 −1.0 0.0 2.4 0.2 −2.8 0.2 −2.9 ΔE* 0.8 0.6 0.40.5 0.3 3.1 3.0 2.7 2.4 2.3 2688 Haze 101 6.08 102 6.66 102 7.09 % Tvis(Y 2/C) 1.75 71.00 1.32 69.75 1.24 69.64 L* (2/C) 14.13 87.49 11.4286.88 10.83 86.82 a* (2/C) 5.23 −0.56 2.69 −0.59 2.15 −0.56 b* (2/C)10.02 5.65 6.76 5.75 6.02 5.53 Δ Haze 0.0 0.1 0.0 0.0 0.0 0.2 −101.5−7.6 −101.5 −7.6 Δ % Tvis (Y 2/C) 0.1 −1.1 0.0 −0.9 0.0 2.1 −1.3 −68.2−1.3 −68.2 ΔE* 1.2 0.6 0.5 0.5 0.2 2.9 13.1 86.3 13.1 86.3 3024 Haze 1015.94 102 6.56 102 6.76 % Tvis (Y 2/C) 1.815 68.29 1.35 69.78 1.27 69.84L* (2/C) 14.47 86.15 11.60 86.89 11.05 86.92 a* (2/C) 5.44 −1.13 2.86−0.58 2.27 −0.55 b* (2/C) 10.48 7.17 6.99 5.77 6.27 5.53 Δ Haze −1.0 0.00.0 −0.1 0.0 −0.2 −101.5 −7.6 −101.5 −7.6 Δ % Tvis (Y 2/C) 0.2 −3.8 0.1−0.9 0.0 2.3 −1.3 −68.2 −1.3 −68.2 ΔE* 1.8 2.6 0.8 0.5 0.4 3.0 13.1 86.313.1 86.3

It is noted that after turning the samples to the on state, it takesabout 8 minutes for the transmission measurements to re-stabilize in theoff state. This was not initially noticed on samples 1, 2, and 3. Offstate measurements were taken once samples stabilized. Only one set ofinitial data for sample 4 was gathered; therefore, it was consideredbaseline data for both the panel and the UV blocked side.

It will be appreciated that it is desirable to reduce the absolutevalues of the changes in haze, percent visible transmission, and E*values over time, for both on and off states. Thus, it is preferable toreduce the absolute value of the change in haze to below about 10, morepreferably below about 5, even more preferably below about 3, even morepreferably below about 2, and most preferably below about 1. Similarly,it is preferable to reduce the absolute value of the change in Tvis(when measure with the Y 2/C method) to below about 5, even morepreferably below about 3, even more preferably below about 2, and mostpreferably below about 1. Again, it is preferable to reduce the changein E* to below about 5, even more preferably below about 3, even morepreferably below about 2, and most preferably below about 1. It will beappreciated that the exposure to UV over time may affect one or both ofthe on and off state measurements. Thus, it may not always be possibleto achieve corresponding reductions to the changes in haze, Tvis, andE*, for both the on and off states, although it is still desirable toachieve reductions to the changes in haze, Tvis, and E*, for one of theon and off states even when it is not possible to achieve correspondingresults for the other state.

As noted above, there sometimes is a problem related to delamination ofcurved laminates with sharp edges proximate to high-stress hot-spots. Tomake curved laminates, certain example embodiments take into account thestiffness of the PET material being used. For example, in certainexample embodiments, to attenuate the z-component of the compressivestress below 100 MPa, the PET/LC/PET layers combined may be provided ata thickness that does not exceed about 300 microns. In addition, or inthe alternative, stress points may be reduced by the use of lasercutting of the raw LC material in certain example embodiments. By way ofexample and without limitation, the LC may be laser cut, e.g., so as toinclude grooves or channels. Such grooves or channels may be located onopposing sides of the stack. In addition to reducing the delamination,these and/or similar grooves also help reduce the formation of wrinkles.

Further details of an example multi-layer low-E UV blocking coating thatmay be used in connection with certain example embodiments is nowprovided. Certain example low-E UV blocking coatings may include a layerstack that may permit the coated article to achieve one or more of highselectivity (T_(vis)/SF), a fairly low solar factor (SF), substantiallyneutral color at normal and/or off-axis viewing angles, and/or lowemissivity. One, two, three, or all of these features may be achieved indifferent embodiments of this invention. When high selectivity(T_(vis)/SF) is achieved, there is provided a high ratio of visibletransmission (T_(vis)) to solar factor (SF), which will be appreciatedby those skilled in the art as being an indication of a combination ofgood visible transmission and good solar protection of a building and/orvehicle interior for example.

In certain example embodiments of this invention, a coated article suchas an IG window unit (e.g., with two spaced apart glass substrates)realizes a high selectivity (T_(vis)/SF) of at least 1.75, morepreferably of at least 1.80, even more preferably of at least 1.85, andsometimes at least 1.90. In certain example embodiments of thisinvention, coated articles realize a high selectivity value, incombination with a SF of no greater than 35.0, and more preferably a SFof no greater than 34.0, even more preferably a SF of no greater than33.0, and most preferably a SF of no greater than 32.5 (SF, or g-value,is calculated in accordance with DIN 67507, the disclosure of which ishereby incorporated herein by reference). This permits coated articles,for example, to realize good selectivity while at the same time blockingsignificant undesirable radiation from reaching a building interior orthe like.

In certain example embodiments of this invention, a coated article isprovided which has both high selectivity and desirable coloration atboth normal and off-axis viewing angles such as 45 degrees from normal.Moreover, in certain example embodiments, the coloration of the coatedarticle does not shift by more than a predetermined amount between anormal viewing angle and an off-axis viewing angle of 45 degrees forexample.

In certain example embodiments of this invention, coated articlesrealize a visible transmission of from about 50 to 70%, more preferablyfrom about 55 to 65%, and most preferably from about 58 to 64% in amonolithic and/or IG unit context.

Sheet resistance (R_(s)) is indicative of emissivity or emittance. Lowsheet resistance is achieved in certain example embodiments of thisinvention. In certain example embodiments of this invention, a coatedarticles realizes a sheet resistance (R_(s)) of no greater than about3.0 ohms/square, more preferably no greater than about 2.0 ohms/square,and most preferably no greater than about 1.9 ohms/square before anyoptional heat treatment such as tempering. Such low sheet resistancevalues are indicative of low emissivity.

In certain example embodiments of this invention, the low-E coating of acoated article includes only two IR reflecting layers (e.g., only twosilver or silver-based layers). While other numbers of IR reflectinglayers may sometimes be provided, the use of two is preferable incertain instances in that low-emittance can be achieved and more suchlayers are not required thereby making coatings easier and costeffective to manufacture and less susceptible to yield problems.

In certain example embodiments of this invention, an IR reflecting layeris located between respective lower and upper contact layers, each ofwhich contacts the IR reflecting layer. The contact layers may be madeof material(s) such as an oxide of nickel-chrome (NiCrO_(x)) in certainexample embodiments of this invention. In certain embodiments, the lowercontact layer is of the sub-oxide type, whereas the upper contact layeris more oxided than is the lower contact layer. Surprisingly andunexpectedly, it has been found that by using a sub-oxide contact layerunder and contacting the IR reflecting layer and a more oxided contactlayer over the IR reflecting layer, significantly higher selectivityvalues and lower SF values may be achieved in combination with desirablecoloration at normal and/or off-axis viewing angles. These representsignificant example advantages in the art.

FIGS. 6 and 7 are example multi-layer low-E UV blocking coatings thatmay be used in connection with certain example embodiments. The coatedarticle includes substrate 202 (e.g., clear, green, bronze, orblue-green glass substrate from about 1.0 to 10.0 mm thick, morepreferably from about 1.0 mm to 7.0 mm thick), and coating (or layersystem) 600 provided on the substrate 202 either directly or indirectly.The coating (or layer system) 600 includes: dielectric titanium oxidelayer 601 which may be TiO_(x) (e.g., where x is from 1.5 to 2.0), firstlower contact layer 603 (which contacts IR reflecting layer 605), firstconductive and preferably metallic infrared (IR) reflecting layer 605,first upper contact layer 607 (which contacts layer 605), dielectriclayer 609 (which may be deposited in one or multiple steps in differentembodiments of this invention), dielectric layer 615 may be of orinclude zinc oxide, second conductive and preferably metallic IRreflecting layer 619, second upper contact layer 621 (which contactslayer 619), dielectric layer 623, and finally protective dielectriclayer 625. The “contact” layers 603, 607, and 621 each contact at leastone IR reflecting layer (e.g., layer based on Ag, Au, or the like). Theaforesaid layers 601-625 make up low-E coating 600 which is provided onglass or plastic substrate 202.

To improve the low-E coating 600 of FIG. 6 and/or the low-E coating 700of FIG. 7 to provide enhanced UV blocking features (e.g., blockage oflight having a wavelength in the range of about 380-400 nm), additionallayers may be added to the stack. For example, in FIG. 6, dielectriclayer 609 may be “split” and an additional UV blocking layer 611 may beadded (e.g., between successive layers of the dielectric layer 609).That is, at least some of dielectric layer 609 may be deposited, the UVblocking layer 611 may be deposited, and then the rest of the dielectriclayer 609 may be deposited. The UV blocking layer may be of or includezinc oxide doped with bismuth (e.g., ZnBiO or other suitablestoichiometry) or simply bismuth oxide (BiO) in certain exampleembodiments. In certain other example embodiments, the UV blocking layer611 may include silver oxide (e.g., AgO_(x) or other suitablestoichiometry), as described, for example, in U.S. Pat. No. 6,596,399,the entire contents of which is hereby incorporated herein by reference.Similarly, in FIG. 7, the dielectric layer 623 may be split and the UVblocking layer 611 may be inserted therein. In still other exampleembodiments, a UV blocking layer 611 surrounded by dielectric layers(e.g., of tin oxide) may be located anywhere in the low-E stack.

The improved low-E UV blocking stacks 600 and 700 thus are capable ofblocking both UV and IR.

Further details of low-E coatings and stacks may be found, for example,in U.S. Pat. No. 7,198,851 or 7,189,458 or U.S. Publication No.2005/0164015, the entire contents of each of which is herebyincorporated herein by reference. For example, dielectric layer 601 maybe of or include titanium oxide in certain example embodiments of thisinvention. This layer is provided for anti-reflective purposes, andpreferably has an index of refraction (n) of from about 2.0 to 2.6, morepreferably from about 2.2 to 2.5. Layer 601 may be provided in directcontact with the glass substrate 202 in certain example embodiments ofthis invention, or alternatively other layer(s) may be provided betweenthe substrate 202 and layer 601 in certain instances.

infrared (IR) reflecting layers 605 and 619 are preferably substantiallyor entirely metallic and/or conductive, and may comprise or consistessentially of silver (Ag), gold, or any other suitable IR reflectingmaterial. IR reflecting layers 605 and 619 help allow the coating tohave low-E and/or good solar control characteristics. The IR reflectinglayers 605 and/or 619 may, however, be slightly oxidized incertain-embodiments of this invention.

Contact layers 607 and 621 may be of or include nickel (Ni) oxide,chromium/chrome (Cr) oxide, or a nickel alloy oxide such as nickelchrome oxide (NiCrO_(x)), or other suitable material(s), in certainexample embodiments of this invention. The use of, for example,NiCrO_(x) in these layers (607 and/or 621) allows durability to beimproved. These contact layers may or may not be continuous in differentembodiments of this invention across the entire IR reflecting layer.

In certain example embodiments of this invention, the upper contactlayers 607 and/or 621 that are located above the respective IRreflecting layers 605 and 619 are deposited in a manner so as to beoxided to a first extent. In certain example embodiments, the uppercontact layers 607 and/or 621 may be substantially fully oxided.

Surprisingly, it has been found that by using an optional sub-oxidecontact layer under and contacting the IR reflecting layer 619 and amore oxided contact layer 621 over the IR reflecting layer 619,significantly higher selectivity values and lower SF values can beachieved in combination with desirable coloration at normal and/oroff-axis viewing angles. In particular, it has been found thatunexpected advantages can be achieved when the optional contact layerunder the IR reflecting layer 619 is deposited in a manner so as to beoxided to a lesser extent than upper contact layer 621 on the other sideof the IR reflecting layer 619. In certain example embodiments, theoptional contact layer an the contact layer 621 may be composed ofoxides of the same metal(s), yet be oxided to different extents wherethe optional lower contact layer is oxided to a lesser extent than isthe upper contact layer 621. For example, in certain example embodimentsof this invention, the optional lower NiCrO_(x) contact layer is asub-oxide (i.e., only partially oxided) whereas upper NiCrO_(x) contactlayer 621 is substantially fully oxided as deposited by sputtering orthe like.

In certain example embodiments of this invention, as deposited and/or inthe final product which is not thermally tempered in certainembodiments, the optional sub-oxide contact layer may have no more thanabout 80% of the oxygen content of the upper contact layer 621, morepreferably no more than about 70% of the oxygen content of the uppercontact layer 621, and most preferably no more than about 60% of theoxygen content of the upper contact layer 621. In each of these cases,as well as others, it will be appreciated that the lower contact layer617 under the IR reflecting layer 619 is oxided to a lesser extent thanis the upper contact layer 621 located over the IR reflecting layer 619in at least certain portions of the respective contact layers.

In order to deposit the optional sub-oxide contact layer in a manner soas to be less oxided than upper contact layer 621, even when they areoxides of the same metal(s) such as Ni and/or Cr, less oxygen gas flowper kW of sputtering power may be used in sputtering the optional layercompared to layer 621. For example, given similar or the same type ofsputtering target(s) (e.g., using NiCr based targets for each layer), anoxygen gas flow of about 5 ml/kW may be used when sputtering theoptional sub-oxide lower contact layer, whereas an oxygen gas flow ofabout 10 ml/kW may be used when sputtering substantially fully oxidedupper contact layer 621 (the remainder of the gas flows may be made upof Ar or the like). In this particular example, the oxygen gas flow perkW of sputtering power for the optional sub-oxide layer is about 50% ofthat for the more oxided upper contact layer 621. In certain exampleembodiments of this invention, the oxygen gas flow per kW of sputteringpower for the optional sub-oxide layer is no more than about 80% of thatused for the upper more oxided contact layer 621, more preferably nomore than about 70% of that used for the upper more oxided contact layer621, and even more preferably no more than about 60% of that used forthe upper more oxided contact layer 621.

In certain example embodiments of this invention, the upper contactlayers 607 and 621 provided over the respective IR reflecting layers maybe deposited in similar or the same manners.

Lower contact layer 603 and/or dielectric layer 615 in certainembodiments of this invention are of or include zinc oxide (e.g., ZnO).The zinc oxide of layer(s) 603, 615 may contain other materials as wellsuch as Al (e.g., to form ZnAlO_(x)). For example, in certain exampleembodiments of this invention, one or more of zinc oxide layers 603, 615may be doped with from about 1 to 10% Al, more preferably from about 1to 5% Al, and most preferably about 2 to 4% Al. The use of zinc oxide603 under the silver 605 allows for an excellent quality of silver to beachieved.

Dielectric layer 609 may be of or include tin oxide in certain exampleembodiments of this invention. However, as with other layers herein,other materials may be used in different instances. Dielectric layer 623may be of or include tin oxide in certain example embodiments of thisinvention. However, layer 623 is optional and need not be provided incertain example embodiments of this invention. Dielectric layer 625,which may be an overcoat including one or more layers in certain exampleinstances, may be of or include silicon nitride (e.g., Si₃N₄) or anyother suitable material in certain example embodiments of thisinvention. Optionally, other layers may be provided above layer 625. Forexample, an overcoat layer of or including zirconium oxide (not shown)may be formed directly on top of the silicon nitride layer 625 incertain example embodiments of this invention. Silicon nitride layer 625may be doped with Al or the like in certain example embodiments of thisinvention.

Other layer(s) below or above the illustrated coating may also beprovided. Thus, while the layer system or coating is “on” or “supportedby” substrate 202 (directly or indirectly), other layer(s) may beprovided therebetween. Thus, for example, the coating of FIG. 6 may beconsidered “on” and “supported by” the substrate 202 even if otherlayer(s) are provided between layer 601 and substrate 202. Moreover,certain layers of the illustrated coating may be removed in certainembodiments, while others may be added between the various layers or thevarious layer(s) may be split With other layer(s) added between thesplit sections in other embodiments of this invention without departingfrom the overall spirit of certain embodiments of this invention. Thus,the use of the word “on” herein is not limited to being in directcontact with.

Certain example embodiments incorporate the illustrate layers describedherein so that no more than about 20% of light having a wavelength ofabout 380-400 nm reaches the PDLC layer. Preferably, less than about 15%of light having a wavelength of about 380-400 nm reaches the PDLC layer.Still more preferably less than about 10%, and most preferably less thanabout 5%, of light having a wavelength of about 380-400 nm reaches thePDLC layer. Certain example embodiments incorporate the illustratelayers described herein so that the visible transmission of light is atleast about 55%, more preferably at least about 60%, still morepreferably at least about 65%, and most preferably at least about 70%.

PVB laminates tend to be more resistant to impact. However, in certainexample instances, PVB laminates sometimes allow the LC layer to moveinwards, degrading the performance and/or appearance of the overallstructure. Thus, in certain example embodiments, a polymer (e.g., of anacrylic or an amide) may be provided at the periphery (e.g., proximate,although not necessarily limited, to the edges) of the PDLC film. Thispolymer may act as barrier, reducing migration of the PVB plasticizer,and reducing the chances of the LC being pushed inwards. Thus, certainexample embodiments may include a polymer barrier proximate to theperiphery of the PDLC film so as to reduce migration of the PVB and/ormovement of the LC layer. It will be appreciated that although themovement of the LC inwards is a problem associated with PVB, a polymerbarrier may be used in connection with other laminates.

Although certain example embodiments have been described in relation tovarious applications, the present invention is not limited thereto. Thetechniques of certain example embodiments may be applied to any glassand/or window-like application, such as, for example, vehiclewindshields, sunroof's, interior and/or exterior windows, IG units, etc.

Also, the features, aspects, advantages, and example embodimentsdescribed herein may be combined to realize yet further embodiments.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiment, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A coated article including a low-E coating supported by a substrate, the low-E coating comprising: first and second infrared (IR) reflecting layers comprising silver and/or gold; at least one UV blocking layer that blocks significant amounts of UV light having a wavelength of from 380-400 nm so that no more than about 20% of light having a wavelength of from 380-400 nm passes through the low-E coating; wherein the UV blocking layer is disposed between the first and second IR reflecting layers, but is positioned so as to not directly contact the first and second IR reflecting layers, and wherein the at least one UV blocking layer is between and in contact with a first and a second tin oxide layer.
 2. The coated article of claim 1, further comprising a first dielectric layer provided between the UV blocking layer and the first IR reflecting layer, and a second dielectric layer provided between the UV blocking layer and the second IR reflecting layer.
 3. The coated article of claim 1, wherein the UV blocking layer comprises zinc oxide doped with bismuth.
 4. The coated article of claim 1, wherein the UV blocking layer comprises bismuth oxide.
 5. The coated article of claim 1, wherein no more than about 15% of light having a wavelength of from 380-400 nm passes through the low-E coating.
 6. The coated article of claim 1, wherein no more than about 10% of light having a wavelength of from 380-400 nm passes through the low-E coating.
 7. The coated article of claim 1, wherein a dielectric layer is disposed between the first and second IR reflecting layers, and the dielectric layer is split such that the UV blocking layer is disposed between the first and second portions of the dielectric layer.
 8. The coated article of claim 1, further comprising at least one lower contact layer disposed under and contacting at least one of the IR reflecting layers, and at least one upper contact layer disposed over and contacting the at least one of the IR reflecting layers, wherein the lower contact layer is oxided to a lesser extent than the upper contact layer.
 9. A coated article including a low-E coating supported by a substrate, the low-E coating comprising, moving away from the substrate: a first infrared (IR) reflecting layer comprising silver and/or gold; a dielectric layer comprising first and second portions; a second IR reflecting layer comprising silver and/or gold; wherein the dielectric layer is split such that at least one UV blocking layer that blocks significant amounts of UV light having a wavelength of from 380-400 nm so that no more than about 20% of light having a wavelength of from 380-400 nm passes through the low-E coating is disposed between the first and second portions of the dielectric layer, and wherein the at least one UV blocking layer is between and in contact with a first and a second tin oxide layer.
 10. The coated article of claim 9, wherein the UV blocking layer comprises bismuth oxide.
 11. The coated article of claim 9, wherein the UV blocking layer comprises bismuth-doped zinc oxide.
 12. The coated article of claim 9, wherein the UV blocking layer comprises silver oxide.
 13. A coated article including a low-E coating supported by a substrate, the low-E coating comprising: a first infrared (IR) reflecting layer comprising silver and/or gold; at least one UV blocking layer that blocks significant amounts of UV light having a wavelength of from 380-400 nm so that no more than about 20% of light having a wavelength of from 380-400 nm passes through the low-E coating; a lower contact layer; a second IR reflecting layer comprising silver and/or gold; and an upper contact layer, wherein the upper contact layer is more oxided than the lower contact layer; wherein the UV blocking layer is positioned so as to not directly contact the first and second IR reflecting layers, and wherein the at least one UV blocking layer is between and in contact with a first and a second tin oxide layer. 